A high-frequency semiconductor device for power amplification has a comb-teeth
electrode on each of active regions formed on the front surface of the semiconductor
substrate. One aspect of the present invention, there is provided a monolithic
microwave integrated circuit (MMIC) having a plurality of rectangular-shaped active
regions arranged side by side on the front surface of the semiconductor substrate,
each of the active regions having interdigited gate, drain and source electrodes
thereon which are connected to the respective pads by multilayer interconnection
technique. Additionally, the source potential is fed from the back surface of the
substrate through a metal plugged via-hole.
